Terminals are typically crimped onto wires by means of a conventional crimping press having an anvil for supporting the electrical terminal and a die that is movable toward and away from the anvil for effecting the crimp. In operation, a terminal is placed on the anvil, an end of a wire is inserted into the ferrule or barrel of the terminal, and the die is caused to move toward the anvil to the limit of the stroke of the press, thereby crimping the terminal onto the wire. The die is then retracted to its starting point.
In order to obtain a satisfactory crimped connection, the crimp height and other characteristics of the crimped terminal must be closely controlled. The crimp height of a terminal is a measure of height or maximum vertical dimension of a given portion of the terminal after crimping. Ordinarily, if a terminal is not crimped to the correct crimp height for the particular terminal and wire combination, an unsatisfactory crimped connection will result. On the other hand many unsatisfactorily crimped connections will, nevertheless, exhibit a "correct" crimp height. A crimp height variance or other physical variation in the crimped terminal is not in and of itself the cause of a defective crimp connection, but rather, is indicative of another factor which causes the poor connection. Such factors include using the wrong terminal or wire size, missing strands of wire, wrong wire type, and incorrect stripping of insulation. Since such defective crimped connections frequently have the appearance of high quality crimped connections, it is difficult to identify these defects so that timely corrective action may be taken.
A simple non-destructive means of detecting such defective crimped connections by accurately measuring crimp height during the crimping process is disclosed in U.S. Pat. No. 4,856,186 which issued Aug. 15, 1989 to Yeomans and U.S. Pat. No. 4,916,810 which issued Apr. 17, 1990 to Yeomans, both of which are incorporated by reference as though set forth verbatim herein.
What is needed is an apparatus and method of use thereof which, utilizing the teachings of the above referenced patents, detects defectively crimped terminals by analyzing the crimping forces imposed on the terminal during the actual crimping operation.